1. Field of the Invention
The present invention relates to a horn switch system for the horn mechanism of a steering wheel of a vehicle or ship, more particularly, to a horn switch system for the steering wheel of a car.
2. Description of the Related Art
In automobiles, the conventional practice is to springingly support a pad on the top center portion of the steering wheel for activation of a horn switch by hand depression.
This type of pad has a plurality of pad legs at suitable positions on its inner face. The legs fit into and engage with pad leg receivers on a contact plate positioned under the pad. At each pad leg position, a compressed spring is interposed between the contact plate and a boss plate positioned beneath the same around a spacer, which supports the contact plate at a different position from the pad leg receiver piece. Therefore, if the pad is depressed, the pad legs press against the contact plate at the positions of the pad leg receivers. The contact plate is pressed down against the compressed spring force along the spacers, whereupon the terminal of the contact plate comes into electrical contact with the boss plate.
In this kind of steering wheel horn switch system, since the pad mounting portion and contact plate supporting portion (spacer mounting portion) are different in position on the contact plate, even when the two portions are arranged close together, space is required for the two portions. Further, the contact plate is a thin plate made light in weight, so, depending on the distance between the position of the pressing action of the pad, that is, the pad mounting position, and the position of the pushing of the contact plate, that is, the point of the pushing up action of the spring (spacer position), a bending action will work on the contact plate at the time of pad depression obstructing smooth up-down movement of the pad.
Still further, since the pad has been mounted to the contact plate to set the contact stroke of the horn, the contact stroke of the horn becomes unstable due to the bending action of the contact plate.